In 2006, Roger Arias went into his garage searching for a long-lost treasure. He remembered a story about his grandmother and a Spanish translation of "The Star-Spangled Banner."

"I dug through my boxes and sure enough, there was a folder," he says. "It said 'The National Anthem,' and she had version 1 through 10. She kept every one of them."

Clotilde Arias wrote the translation at the end of World War II, as President Franklin Roosevelt was trying to win allies through cultural exchange. Roosevelt sent artists like Walt Disney and Orson Welles to Latin America, and commissioned translations of patriotic songs to send abroad. Marvette Perez, a curator at the Smithsonian Institution in Washington, D.C., says the move was an effort to spread patriotism to other countries.

"They wanted Latin America to know how great a country the U.S. was," she says. "What better way than through the national anthem?"

Perez says the State Department already had translations of the anthem in other languages, including Japanese, German and even Yiddish — but that doesn't mean they could be sung.

"They wanted a singable one," she says. "They wanted people to be able to sing it, and Clotilde Arias apparently did a marvelous job."

Arias' version of the anthem is now part of an exhibit at the Smithsonian Institution in Washington, D.C. The museum couldn't find any recordings of Arias' translation, so it commissioned a D.C.-based choir called Coral Cantigas to bring it back to life.

Arias' son Roger — who is now 82 — was at the opening of the exhibit. He says he remembers his mother sitting at the piano in their Brooklyn apartment, working on draft after draft.

"I was there when she was writing it," Roger Arias says. "She'd sing it in her own way to see if it fits, and she would say, 'How does that sound, sonny?' And I would say anything she did sounded good to me. So, yes, she struggled through it, but she made it work."

Clotilde Arias was born in the small Peruvian city of Iquitos in 1901. A lover of music, she moved to New York City to become a composer when she was 22. She started working for ad agencies and writing jingles for big-name American companies, including Alka-Seltzer, Ford Motor Co. and Campbell's Soup.

Maneuvering into professions dominated by men, Arias excelled. But her family says she was most proud of "El Pendon Estrellado" — her translation of "The Star Spangled Banner."

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AUDIE CORNISH, HOST:

"The Star-Spangled Banner" is notoriously hard to sing. Back in 1945, the U.S. government commissioned a singable version of the national anthem, in Spanish. It paid a Peruvian immigrant to do the translation. Over the decades, her version was forgotten, and nearly lost. Now, you can hear it as part of a new exhibit at the Smithsonian, here in Washington. NPR's Lauren Silverman takes a listen.

LAUREN SILVERMAN, BYLINE: In 2006, Roger Arias II went into his garage, searching for a long-lost treasure. He remembered a story about his grandmother, and a Spanish translation of the national anthem.

ROGER ARIAS II: I dug through my boxes. And sure enough, there was a folder, and it said "The National Anthem." And she had version one through 10. She kept every one of them.

(SOUNDBITE OF SONG, "THE STAR-SPANGLED BANNER")

SILVERMAN: Clotilde Arias wrote the translation at the end of World War II. President Franklin Roosevelt was trying to win allies through cultural exchange. So he sent artists - like Walt Disney and Orson Welles - to Latin America, and commissioned translations of patriotic songs to send abroad.

MARVETTE PEREZ: They wanted Latin America to know how great a country the U.S. was, and what better way than through the national anthem?

SILVERMAN: That's Marvette Perez, the curator of the exhibit showcasing the Spanish translation. She explains the State Department already had translations of the national anthem in other languages - in Japanese, German, even Yiddish. But...

PEREZ: That doesn't mean they can be sung. They wanted a singable one. They wanted people to be able to sing it; and Clotilde Arias, apparently, did a marvelous job.

SILVERMAN: The museum couldn't find any recordings of Arias' translation, so they commissioned a Washington, D.C.-based choir called Coral Cantigas, to bring it back to life.

(SOUNDBITE OF SONG, "THE STAR-SPANGLED BANNER")

SILVERMAN: Clotilde Aria's son, who's now 82, was at the opening of the exhibit.

ROGER ARIAS: I was there when she was writing it.

SILVERMAN: Roger Arias remembers his mother sitting at the piano in their Brooklyn apartment, working on draft after draft.

ARIAS: She'd sing it in her own way to see if it fits and she says, how does that sound, sonny? And I says - anything she did, sounded good to me. But yes, she struggled through it; but it made it work.

SILVERMAN: Clotilde Arias was born in the small Peruvian city of Iquitos, in 1901. She loved music and at 22, moved to New York City to become a composer. She started working for ad agencies, writing jingles for big name American companies, like Alka Seltzer...

(SOUNDBITE OF ALKA SELTZER AD)

SILVERMAN: ...Ford Motor Company...

(SOUNDBITE OF FORD MOTOR COMPANY AD)

SILVERMAN: ...and Campbell's Soup.

(SOUNDBITE OF CAMPBELL'S SOUP AD)

SILVERMAN: Clotilde Arias maneuvered into professions dominated by men. And she excelled. But her grandson says she was most proud of "El Pendon Estrellado," her translation of "The Star Spangled Banner."